Work is advanced initially, following my closely focused vision (6)
I believe the answer is:
myopia
'closely focused vision' is the definition.
'work is advanced initially following my' is the wordplay.
'work' becomes 'op' (abbreviation for opus**).
'initially' indicates taking the first letters.
'following' says to put letters next to each other.
The first letters of 'is advanced' is 'ia'.
'op'+'ia'='opia'
'opia' after 'my' is 'MYOPIA'.
(Other definitions for myopia that I've seen before include "Seeing problem" , "Short-sightedness" , "lack of long-term vision" , "vision problem" , "Condition of short sightedness" .)